Research

Birds

Habitat use and segregation of rails of the genus Porzana
Spotted crake (Porzana parva)

All seven species of rail occur on the restored and re-wetted areas in the valley of the river Peene. This includes the three species of Porzana, P. porzana, P. parva and P. pusilla. The latter was thought to be extinct in Germany. We are interested in the habitat requirements of these three species during the breeding season in order to understand how these closely related species can co-exist. We investigate abiotic and biotic characteristics of habitats as well as spatial and temporal use of territories, intra- and interspecific territorial behavior, and social interactions. In this context, we have an additional focus on the more common Water Rail, which probably also interacts with the Porzana species. These investigations are also complemented by molecular approaches in order to answer population genetic and demographic questions. The ultimate goal is the elaboration of conservation and management measures aiming at the permanent establishment of these rail populations.

Scientists involved: Dipl.-Biol. Alexander Eilers, Dr. Angela Schmitz, Dipl.-Biol. Benjamin Herold, Dr. Martin Haase
Financing:http://www.brehm-fonds.de/de/projekte/heimliche-bewohner-des-rohrdschungels-rallen/Brehm Fonds für den internationalen Vogelschutz, Bonn

Effects of changes of climate and land use on the phenology of bird communities

Climate change has meanwhile been recognized as cause for many phenological changes such as timing of migration, failure of synchronization with prey or distributional shifts in birds. However, our understanding of the causal relations between climate change and phenology, the immediate triggers and consequences of phenological changes is still in its infancies. We particularly lack long term studies in order to address these questions properly. An additional difficulty in studying climate effects is posed by the entanglement of effects due to change of land use. Continuous surveys over five decades in the area of the Müritz Nationalpark offer unique possibilities for deepening our understanding of phenological changes in birds. Due to the long tradition in nature conservation large areas have been near-natural or entirely undisturbed for decades minimizing potential effects of land use change. Due to these unique conditions it can be expected that the analyses will be of general and not only regional relevance for understanding causes of and consequences for bird phenology in the context of climate.

Scientists involved: Dipl.-Biol. Melanie Böhm, Dr. Angela Schmitz; Dr. M. Schwabe (Nationalpark Müritz)
Financing: Landesgraduiertenstipendium Mecklenburg-Vorpommern

Plumage coloration in phylogenetic and evolutionary analyses

Die Färbung des Gefieders von Vögeln spielt bei vielen Arten eine maßgebliche Rolle bei der Partnerwahl und steht somit unter sexueller Selektion. Die Gefiederfärbung hat daher bei der Artbildung eine wichtige Funktion, was seinen Niederschlag auch in der Taxonomie findet. So wichtig das Gefieder in der Unterscheidung von Arten ist, so schwierig war es bisher, diesen Merkmalskomplex für die phylogenetische Analyse heranzuziehen. Dr. Angela Schmitz hat eine Methode entwickelt, objektiv gemessene Farbspektraldaten für kladistische Analysen zu kodieren. Moderne phylogenetische Analysen beruhen heute maßgeblich auf genetischen Daten. Allerdings stellte es sich bei zahlreichen Vogelgruppen heraus, dass genetische Standard-Marker wie mitochondrielle Gene nur wenig zwischenartliche Variabilität zeigen und daher für die Ermittlung von Verwandtschaftsverhältnissen auf dem Artniveau nur bedingt brauchbar sind. V.a. für Gruppen, bei denen die Gefiederfärbung offensichtlich eine bedeutende Rolle in der Speziation spielt, könnten daher Farbspektraldaten eine wichtige Ergänzung zu genetischen Daten darstellen. Dies wird anhand von Analysen von genetischen und Farbspektraldaten von Kolibris untersucht.

Mitarbeiter: Dr. Angela Schmitz, Dr. Martin Haase
Finanzierung: Deutsche Forschungsgemeinschaft; Alexander Koenig Foundation, Bonn; Brehm Fonds für den internationalen Vogelschutz, Bonn; Short-Term visitor appointment, Smithsonian Institution, Washington DC; Collections’ Study Grant, American Museum of Natural History, New York; Jessup Grant, Academy of Natzral Sciences, Philadelphia; SYNTHESYS (the European Union-funded Integrated Infrastructure Initiative grant)

On the function of eggshell colour patterns
© Katja Rahn

An individual of the colonial breeding Black-headed Gull (Chroicocephalus ridibundus) produces per season only a few offspring with long parental care. It requires great energy input. In such colonies it has been found thet intraspecific brood parasitism occur naturally in almost a quarter of cases. Each female lays eggs, that are different in colour and spotting pattern. The aim of the study is to investigate, if they may have developed mechanisms for recognizing their own eggs, like an individual colour "fingerprint" or if the pattern depends on other factors of the bird or the environment.


Scientists involved: M.Sc. Katja Rahn, Dr. Angela Schmitz-Ornes

Population structure and effects of stress and age on the reproductive success of Common cranes (Grus grus)
© Isabel Barwisch

Since the end of the 19th century continuously positive population developments of the Common cranes (Grus grus) have been observed over the European continent, despite intensive agricultural and silvicultural usage (Leito et al. 2003; Boldt 2015). Besides the increasing total numbers of individuals, the distribution range of Common cranes is also growing, showing recent expansions towards Western and Southern Germany and Europe, respectively (Lehrmann 2018). However, recent studies suggest a decreased reproductive success within several areas of high population densities, like in the German federal states Mecklenburg-Western Pomerania and Brandenburg (Mewes 2014). Density-dependent decreases of reproductive success have been documented for other bird species, like Mute swans (Cygnus olor) and Barnacle geese (Branta leucopsis), already (Nummi & Saari 2003; Larsson & Forslund 1994). High population densities intensify competition for territories, good nesting sites and food sources (Fernandez et al. 1998). Whereas only 8 % of the population in Mecklenburg-Western Pomerania and Brandenburg nested within agricultural landscapes, accounted as suboptimal habitats, in 1996, this proportion increased to more than 30 % in 2010 and rising (Mewes 2010). Which factors really are affecting the reproductive success of Common cranes?

The main objectives of this research project are the analysis of the current demographic situation of the European population of Common cranes and to identify factors affecting survival and reproductive success along their geographical range.

Effects of different landscape features or population densities will not only be analyzed from an ecological and behavioural perspective, but also from an physiological perspective by analyzing stress hormones. Individuals breeding within areas of high population densities might suffer from higher stress levels due to intraspecific competition and a lack of suitable nesting habitats and feeding grounds. Since more experienced individuals might be more successful at coping with stressful situations, age could also have an effect.

This study aims at establishing a general basis for future research on cranes and results shall be available for deriving conservation implications and management efforts.

Scientists involved: M.Sc. Isabel Barwisch, Dr. Angela Schmitz Ornés

Snails

Quantifying genetic and environmental effects in adaptation to different habitats in the morphologically variable New Zealand mud snail Potamopyrgus antipodarum

Due to anthropogenic influence, more and more environmental changes are having a great impact on the Earth and on the organisms living on it. Generally, there are three options how organisms can react to environmental changes in their habitat: extinction, migration and adaptation. If they are unable to disperse or to adapt, their risk of extinction is increasing. Others are highly adaptable and easily cope with new and changing environments. Invasive species, for example, are colonizing new habitats with few individuals and are supposed to suffer from reductions in their genetic diversity due to the founder effect. Nevertheless, various invasive species, as the New Zealand mud snail, Potamopyrgus antipodarum, are able to cope well with different environmental conditions and stress and reproduce successfully. Moreover, some of these organisms show traits that are highly variable in different environments. Even within one genotype one can observe different phenotypes under different or changing environmental circumstances (phenotypic plasticity). The shells of P. antipodarum show a high, habitat-depending variability and the shell morphology is adaptive and genetically as well as phenotypically highly plastic. In its native habitat New Zealand, it reproduces diploid-sexually or polyploidy-asexually via parthenogenesis. In invaded regions, such as Australia, Japan, Chile, USA and many European countries, only polyploid, hence asexually reproducing lineages are found.

We aim to disentangle genetic and environmental effects in both common garden and transplant experiments. In common garden experiments, we will estimate heritability of the variability of the shell morphology of P. antipodarum using geometric morphometrics.Using reciprocal transplant experiments, we want toexamine reactions of the snails to changing habitats under most natural conditions possible. Since phenotypic plasticity is apparently very important for P. antipodarum to colonize various types of habitats, we furthermore plan to analyse genome-wide methylation patterns from native and invasive individuals of different habitats using the Nanopore technology in collaboration with Bernhard Misof and Lars Podsiadlowski (Bonn) and relate the methylation patterns to habitat and climate variables as well as shell morphology. In order to identify genes, we will map our data against the genome of P. antipodarum, which is currently being annotated by our project partner Maurine Neiman (Iowa).

Scientists involved: M.Sc. Lisa Männer, Dr. Martin Haase